Bioaccumulation of perfluoroalkyl carboxylates (PFCAs) and perfluoroalkane sulfonates (PFSAs) by earthworms (Eisenia fetida) in soil

Earthworms were exposed to artificially contaminated soils with ten perfluoroalkyl substances (PFASs). PFASs with longer perfluorinated carbon chain displayed higher uptake rate coefficients (ku), longer half-life (t1/2) and time to steady-state (tss) but lower elimination rate coefficients (ke) than the shorter ones. Similarly, perfluorosulfonates acids (PFSAs) displayed higher ku, longer t1/2 and tss but lower ke than perflurocarboxylic acids (PFCAs) with the same perfluorinated chain length. All the studied PFASs, including those with seven or less perfluorinated carbons, were bioaccumulated in the earthworms and the biota-to-soil accumulation factors (BSAFs) increased with perfluorinated carbon chain length and were greater for PFSAs than for PFCAs of equal perfluoroalkyl chain length. The BSAFs were found to be dependent on the concentrations of PFASs in soil and decreased as the level of PFASs in soil increased. •PFASs with seven or less perfluoroalkyl carbons were bioaccumulated in earthworm.•The BSAFs of PFASs in earthworm increased with perfluoroalkyl chain length.•The BSAFs of PFSAs were greater than PFCAs of equal perfluoroalkyl chain length.•The ku increased with perfluorinated chain length while ke decreased.•The BSAFs of PFASs decreased as their concentrations in soil increased. Perfluoroalkyl substances (PFASs) can be effectively bioaccumulated in earthworms including those with seven or less perfluoroalkyl carbon chain length.